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package filter;

import entity.Person;
import entity.PersonService;


import java.io.IOException;
import java.io.PrintStream;
import java.io.PrintWriter;
import java.io.StringWriter;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import util.LoginManager;

/**
 *
 * @author Administrator
 */
public class LoginFilter implements Filter {

    // The filter configuration object we are associated with.  If
    // this value is null, this filter instance is not currently
    // configured. 
    private FilterConfig filterConfig = null;

    public LoginFilter() {
    }

    private void doBeforeProcessing(ServletRequest servletRequest, ServletResponse response)
            throws IOException, ServletException {
        if (debug) {
            log("LoginFilter:DoBeforeProcessing");
        }

        if (((HttpServletRequest) servletRequest).getSession(true).getAttribute("personID") != null)//logined
        {
            return;
        }
        HttpServletRequest request = ((HttpServletRequest) servletRequest);
        HttpSession session = request.getSession(true);
        Cookie[] loginCookies = request.getCookies();
        if (loginCookies != null) {
            for (Cookie c : loginCookies) {
                if ("loginname".equals(c.getName())) {//todo: change MD5 login hash cookies later
                    //login from "remember me"
                    Person p = PersonService.getByLoginname(c.getValue());
                    if (p != null) { //valid login information
                        LoginManager.login(session, p.getLastname(), p.getPersonID());
                        return;//login done
                    }
                }
            }
        }
        //todo: if using SSL can't use the dispatcher..........
        filterConfig.getServletContext().getRequestDispatcher("/login.jsp?msg=nologin").forward(servletRequest, response);
        return;

    }

    private void doAfterProcessing(ServletRequest request, ServletResponse response)
            throws IOException, ServletException {
        if (debug) {
            log("LoginFilter:DoAfterProcessing");

        }
    }

    /**
     *
     * @param request The servlet request we are processing
     * @param response The servlet response we are creating
     * @param chain The filter chain we are processing
     *
     * @exception IOException if an input/output error occurs
     * @exception ServletException if a servlet error occurs
     */
    public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain chain)
            throws IOException, ServletException {

        if (debug) {
            log("LoginFilter:doFilter()");
        }
        doBeforeProcessing(request, response);

        Throwable problem = null;

        try {
            chain.doFilter(request, response);
        } catch (Throwable t) {
            //
            // If an exception is thrown somewhere down the filter chain,
            // we still want to execute our after processing, and then
            // rethrow the problem after that.
            //
            problem = t;
            t.printStackTrace();
        }
        doAfterProcessing(request, response);

        //
        // If there was a problem, we want to rethrow it if it is
        // a known type, otherwise log it.
        //
        if (problem != null) {
            if (problem instanceof ServletException) {
                throw (ServletException) problem;
            }
            if (problem instanceof IOException) {
                throw (IOException) problem;
            }
            sendProcessingError(problem, response);
        }
    }

    /**
     * Destroy method for this filter 
     *
     */
    public void destroy() {
    }

    /**
     * Init method for this filter 
     *
     */
    public void init(FilterConfig filterConfig) {

        this.filterConfig = filterConfig;
        if (filterConfig != null) {
            if (debug) {
                log("LoginFilter:Initializing filter");
            }
        }
    }

    private void sendProcessingError(Throwable t, ServletResponse response) {

        String stackTrace = getStackTrace(t);

        if (stackTrace != null && !stackTrace.equals("")) {

            try {

                response.setContentType("text/html");
                PrintStream ps = new PrintStream(response.getOutputStream());
                PrintWriter pw = new PrintWriter(ps);
                pw.print("<html>\n<head>\n<title>Error</title>\n</head>\n<body>\n"); //NOI18N

                // PENDING! Localize this for next official release
                pw.print("<h1>The resource did not process correctly</h1>\n<pre>\n");
                pw.print(stackTrace);
                pw.print("</pre></body>\n</html>"); //NOI18N
                pw.close();
                ps.close();
                response.getOutputStream().close();
            } catch (Exception ex) {
            }
        } else {
            try {
                PrintStream ps = new PrintStream(response.getOutputStream());
                t.printStackTrace(ps);
                ps.close();
                response.getOutputStream().close();
            } catch (Exception ex) {
            }
        }
    }

    public static String getStackTrace(Throwable t) {

        String stackTrace = null;

        try {
            StringWriter sw = new StringWriter();
            PrintWriter pw = new PrintWriter(sw);
            t.printStackTrace(pw);
            pw.close();
            sw.close();
            stackTrace = sw.getBuffer().toString();
        } catch (Exception ex) {
        }
        return stackTrace;
    }

    public void log(String msg) {
        filterConfig.getServletContext().log(msg);
    }
    private static final boolean debug = true;
}